Seismic Behavior and Functional Loss of Swing-Type Steel Doors within Partition Walls

Doors, with a focus on swing-type steel doors in this study, serve as critical passageways for escape and rescue during earthquakes. However, operational difficulties with doors have been reported in existing studies. Despite this, the functional loss of doors has not received sufficient attention. Previous experiments have only briefly documented the observed phenomena, as doors were considered ancillary components of partition walls. Rotation has been regarded as the mechanism underlying the functional loss of doors, yet it fails to fully account for the experimental phenomena. The assessment of door functional loss has traditionally been based on the door’s state, neglecting the physical strength of users. Therefore, this study investigates the functional loss of doors through a quasi-static test, exploring the associated phenomena, mechanisms, and consequences. A well-designed test program ensures that the results realistically reflect engineering conditions. The phenomena revealed variations in the gaps within the door across different positions and orientations. A mechanism combining rigid body motions and deformations was developed and validated to elucidate the functional loss of doors. By considering the physical strength of users, the functional loss of doors and the effects of improvements were reasonably assessed. The findings are anticipated to be applied in industrial manufacturing and postearthquake rescue efforts.